1. Field of the Invention
The present invention relates to an apparatus for applying an adhesive onto veneers having an obliquely-cut face for scarf joint (hereinafter referred to as scarf-cut face).
2. Description of the Related Art
One example of conventional apparatus for applying an adhesive on a scarf-cut face of a pre-worked veneer as shown in FIG. 1 is disclosed in JAPANESE UTILITY MODEL LAYING-OPEN GAZETTE No. H-1-13,301. In this conventional structure, an adhesive stored in an adhesive reservoir is fed to a supply valve unit 131 by a pressure-feed pump. The adhesive is supplied from the supply valve unit 131 onto a belt 129 spanning in a direction perpendicular to a veneer-feeding direction while the belt 129 goes half round to make a line of adhesive 141 adhere to the belt 129. The line of adhesive 141 is taken up onto a scarf-cut face 105a of a veneer and then spread over the whole scarf-cut face 105a by a rolling belt 155.
The conventional adhesive-applying apparatus constructed as above has drawbacks described below. The pressure-feed pump has upper-limit and lower-limit pressures preset for ensuring safe and smooth operations of the pump, and is controlled to work in a pressure range between the upper limit and the lower limit. The pressure applied during operation of the pressure pump is accordingly varied in the pressure range between the upper limit and the lower limit. This results in variation in the amount of adhesive supplied from the supply valve unit 131. The amount of adhesive supplied from the supply valve unit 131 is also varied with the viscosity of the adhesive. The conventional apparatus requires a relatively complicated mechanism to realize the adhesive taken-up process and the spread-out process.